<?php
/**
 * NIS2 Agile - Policy Controller
 *
 * Gestione policy e procedure di sicurezza, con AI generation.
 */

require_once __DIR__ . '/BaseController.php';
require_once APP_PATH . '/services/AIService.php';
require_once APP_PATH . '/services/WebhookService.php';

class PolicyController extends BaseController
{
    public function list(): void
    {
        $this->requireOrgAccess();

        $where = 'organization_id = ?';
        $params = [$this->getCurrentOrgId()];

        if ($this->hasParam('status')) {
            $where .= ' AND status = ?';
            $params[] = $this->getParam('status');
        }
        if ($this->hasParam('category')) {
            $where .= ' AND category = ?';
            $params[] = $this->getParam('category');
        }

        $policies = Database::fetchAll(
            "SELECT p.*, u.full_name as approved_by_name
             FROM policies p
             LEFT JOIN users u ON u.id = p.approved_by
             WHERE p.{$where}
             ORDER BY p.category, p.title",
            $params
        );

        $this->jsonSuccess($policies);
    }

    public function create(): void
    {
        $this->requireOrgRole(['org_admin', 'compliance_manager']);
        $this->validateRequired(['title', 'category']);

        $policyId = Database::insert('policies', [
            'organization_id' => $this->getCurrentOrgId(),
            'title'           => trim($this->getParam('title')),
            'category'        => $this->getParam('category'),
            'nis2_article'    => $this->getParam('nis2_article'),
            'content'         => $this->getParam('content'),
            'next_review_date' => $this->getParam('next_review_date'),
            'ai_generated'    => $this->getParam('ai_generated', 0),
        ]);

        $this->logAudit('policy_created', 'policy', $policyId);
        $this->jsonSuccess(['id' => $policyId], 'Policy creata', 201);
    }

    public function get(int $id): void
    {
        $this->requireOrgAccess();

        $policy = Database::fetchOne(
            'SELECT p.*, u.full_name as approved_by_name
             FROM policies p
             LEFT JOIN users u ON u.id = p.approved_by
             WHERE p.id = ? AND p.organization_id = ?',
            [$id, $this->getCurrentOrgId()]
        );

        if (!$policy) {
            $this->jsonError('Policy non trovata', 404, 'POLICY_NOT_FOUND');
        }

        $this->jsonSuccess($policy);
    }

    public function update(int $id): void
    {
        $this->requireOrgRole(['org_admin', 'compliance_manager']);

        $updates = [];
        foreach (['title', 'content', 'category', 'nis2_article', 'status', 'version', 'next_review_date'] as $field) {
            if ($this->hasParam($field)) {
                $updates[$field] = $this->getParam($field);
            }
        }

        if (!empty($updates)) {
            Database::update('policies', $updates, 'id = ? AND organization_id = ?', [$id, $this->getCurrentOrgId()]);
            $this->logAudit('policy_updated', 'policy', $id, $updates);
        }

        $this->jsonSuccess($updates, 'Policy aggiornata');
    }

    public function delete(int $id): void
    {
        $this->requireOrgRole(['org_admin']);

        $deleted = Database::delete('policies', 'id = ? AND organization_id = ?', [$id, $this->getCurrentOrgId()]);
        if ($deleted === 0) {
            $this->jsonError('Policy non trovata', 404, 'POLICY_NOT_FOUND');
        }

        $this->logAudit('policy_deleted', 'policy', $id);
        $this->jsonSuccess(null, 'Policy eliminata');
    }

    public function approve(int $id): void
    {
        $this->requireOrgRole(['org_admin']);

        Database::update('policies', [
            'status'      => 'approved',
            'approved_by' => $this->getCurrentUserId(),
            'approved_at' => date('Y-m-d H:i:s'),
        ], 'id = ? AND organization_id = ?', [$id, $this->getCurrentOrgId()]);

        $this->logAudit('policy_approved', 'policy', $id);

        $policy = Database::fetchOne('SELECT * FROM policies WHERE id = ?', [$id]);

        // Snapshot versione per storico/diff/attestation (P3)
        try {
            Database::insert('policy_versions', [
                'policy_id'       => $id,
                'organization_id' => $this->getCurrentOrgId(),
                'version'         => $policy['version'] ?? '1.0',
                'content'         => $policy['content'] ?? null,
                'change_note'     => $this->getParam('change_note') ?: 'Approvazione',
                'created_by'      => $this->getCurrentUserId(),
            ]);
        } catch (Throwable $e) {
            error_log('[POLICY_VER] ' . $e->getMessage());
        }

        // Dispatch webhook policy.approved
        try {
            (new WebhookService())->dispatch(
                $this->getCurrentOrgId(),
                'policy.approved',
                WebhookService::policyPayload($policy)
            );
        } catch (Throwable $e) {
            error_log('[WEBHOOK] dispatch error: ' . $e->getMessage());
        }

        $this->jsonSuccess(null, 'Policy approvata');
    }

    public function aiGeneratePolicy(): void
    {
        $this->requireOrgRole(['org_admin', 'compliance_manager']);
        $this->validateRequired(['category']);

        $category = $this->getParam('category');
        $org = Database::fetchOne('SELECT * FROM organizations WHERE id = ?', [$this->getCurrentOrgId()]);

        try {
            $aiService = new AIService();
            $generated = $aiService->generatePolicy($category, $org);

            $aiService->logInteraction(
                $this->getCurrentOrgId(),
                $this->getCurrentUserId(),
                'policy_draft',
                "Generate {$category} policy",
                substr($generated['title'] ?? '', 0, 500)
            );

            $this->jsonSuccess($generated, 'Policy generata dall\'AI');
        } catch (Throwable $e) {
            $this->jsonError('Errore AI: ' . $e->getMessage(), 500, 'AI_ERROR');
        }
    }

    public function getTemplates(): void
    {
        $this->requireOrgAccess();

        $templates = [
            ['category' => 'information_security', 'title' => 'Politica di Sicurezza delle Informazioni', 'nis2_article' => '21.2.a'],
            ['category' => 'access_control', 'title' => 'Politica di Controllo degli Accessi', 'nis2_article' => '21.2.i'],
            ['category' => 'incident_response', 'title' => 'Piano di Risposta agli Incidenti', 'nis2_article' => '21.2.b'],
            ['category' => 'business_continuity', 'title' => 'Piano di Continuità Operativa', 'nis2_article' => '21.2.c'],
            ['category' => 'supply_chain', 'title' => 'Politica di Sicurezza della Supply Chain', 'nis2_article' => '21.2.d'],
            ['category' => 'encryption', 'title' => 'Politica sulla Crittografia', 'nis2_article' => '21.2.h'],
            ['category' => 'hr_security', 'title' => 'Politica di Sicurezza delle Risorse Umane', 'nis2_article' => '21.2.i'],
            ['category' => 'asset_management', 'title' => 'Politica di Gestione degli Asset', 'nis2_article' => '21.2.i'],
            ['category' => 'network_security', 'title' => 'Politica di Sicurezza della Rete', 'nis2_article' => '21.2.e'],
            ['category' => 'vulnerability_management', 'title' => 'Politica di Gestione delle Vulnerabilità', 'nis2_article' => '21.2.e'],
        ];

        $this->jsonSuccess($templates);
    }

    // ══════════════════════════════════════════════════════════════════════
    // ATTESTATION + VERSIONING (P3)
    // ══════════════════════════════════════════════════════════════════════

    /** POST /api/policies/{id}/attest — dipendente prende visione (versione corrente). */
    public function attest(int $id): void
    {
        $this->requireOrgAccess();
        $policy = Database::fetchOne(
            "SELECT id, version, status FROM policies WHERE id = ? AND organization_id = ? AND deleted_at IS NULL",
            [$id, $this->getCurrentOrgId()]
        );
        if (!$policy) {
            $this->jsonError('Policy non trovata', 404, 'NOT_FOUND');
        }
        if ($policy['status'] !== 'approved') {
            $this->jsonError('Si puo attestare solo una policy approvata', 422, 'NOT_APPROVED');
        }
        $version = $policy['version'] ?? '1.0';

        $existing = Database::fetchOne(
            'SELECT id FROM policy_attestations WHERE policy_id = ? AND user_id = ? AND version = ?',
            [$id, $this->getCurrentUserId(), $version]
        );
        if ($existing) {
            $this->jsonSuccess(['already' => true, 'version' => $version], 'Presa visione gia registrata');
            return;
        }

        Database::insert('policy_attestations', [
            'policy_id'       => $id,
            'organization_id' => $this->getCurrentOrgId(),
            'user_id'         => $this->getCurrentUserId(),
            'version'         => $version,
            'ip_address'     => $this->attClientIp(),
        ]);
        $this->logAudit('policy_attested', 'policy', $id, ['version' => $version]);
        $this->jsonSuccess(['version' => $version], 'Presa visione registrata', 201);
    }

    /** GET /api/policies/{id}/attestations — copertura % presa visione (versione corrente). */
    public function attestations(int $id): void
    {
        $this->requireOrgRole(['org_admin', 'compliance_manager', 'board_member', 'auditor']);
        $policy = Database::fetchOne(
            "SELECT id, title, version FROM policies WHERE id = ? AND organization_id = ? AND deleted_at IS NULL",
            [$id, $this->getCurrentOrgId()]
        );
        if (!$policy) {
            $this->jsonError('Policy non trovata', 404, 'NOT_FOUND');
        }
        $version = $policy['version'] ?? '1.0';

        $members = Database::fetchAll(
            'SELECT u.id, u.full_name, u.email FROM user_organizations uo
             JOIN users u ON u.id = uo.user_id
             WHERE uo.organization_id = ? AND u.is_active = 1',
            [$this->getCurrentOrgId()]
        );
        $attested = Database::fetchAll(
            'SELECT user_id, attested_at FROM policy_attestations WHERE policy_id = ? AND version = ?',
            [$id, $version]
        );
        $attMap = [];
        foreach ($attested as $a) { $attMap[(int) $a['user_id']] = $a['attested_at']; }

        $list = array_map(fn($m) => [
            'user_id'     => (int) $m['id'],
            'full_name'   => $m['full_name'],
            'email'       => $m['email'],
            'attested'    => isset($attMap[(int) $m['id']]),
            'attested_at' => $attMap[(int) $m['id']] ?? null,
        ], $members);

        $total = count($members);
        $done = count(array_filter($list, fn($x) => $x['attested']));
        $this->jsonSuccess([
            'policy_id'        => $id,
            'version'          => $version,
            'total_members'    => $total,
            'attested'         => $done,
            'coverage_percent' => $total ? (int) round($done * 100 / $total) : 0,
            'members'          => $list,
        ]);
    }

    /** GET /api/policies/{id}/versions — storico versioni. */
    public function versions(int $id): void
    {
        $this->requireOrgAccess();
        $rows = Database::fetchAll(
            'SELECT id, version, change_note, created_by, created_at FROM policy_versions
             WHERE policy_id = ? AND organization_id = ? ORDER BY created_at DESC',
            [$id, $this->getCurrentOrgId()]
        );
        $this->jsonSuccess(['versions' => $rows]);
    }

    /** GET /api/policies/{id}/diff?from={vId}&to={vId} — diff line-by-line. */
    public function diff(int $id): void
    {
        $this->requireOrgAccess();
        $fromId = (int) $this->getParam('from');
        $toId   = (int) $this->getParam('to');
        $a = Database::fetchOne('SELECT version, content FROM policy_versions WHERE id = ? AND policy_id = ? AND organization_id = ?', [$fromId, $id, $this->getCurrentOrgId()]);
        $b = Database::fetchOne('SELECT version, content FROM policy_versions WHERE id = ? AND policy_id = ? AND organization_id = ?', [$toId, $id, $this->getCurrentOrgId()]);
        if (!$a || !$b) {
            $this->jsonError('Versione non trovata', 404, 'NOT_FOUND');
        }
        $linesA = preg_split('/\r\n|\r|\n/', (string) $a['content']);
        $linesB = preg_split('/\r\n|\r|\n/', (string) $b['content']);
        $setA = array_count_values(array_map('trim', $linesA));
        $setB = array_count_values(array_map('trim', $linesB));
        $added = []; $removed = [];
        foreach ($linesB as $l) { $t = trim($l); if ($t !== '' && empty($setA[$t])) $added[] = $l; }
        foreach ($linesA as $l) { $t = trim($l); if ($t !== '' && empty($setB[$t])) $removed[] = $l; }
        $this->jsonSuccess([
            'from'    => ['id' => $fromId, 'version' => $a['version']],
            'to'      => ['id' => $toId,   'version' => $b['version']],
            'added'   => $added,
            'removed' => $removed,
            'summary' => ['added' => count($added), 'removed' => count($removed)],
        ]);
    }

    /** GET /api/policies/pending-attestations — policy approvate non ancora attestate dall'utente. */
    public function pendingAttestations(): void
    {
        $this->requireOrgAccess();
        $rows = Database::fetchAll(
            "SELECT p.id, p.title, p.category, p.version, p.approved_at
             FROM policies p
             WHERE p.organization_id = ? AND p.status = 'approved' AND p.deleted_at IS NULL
               AND NOT EXISTS (
                   SELECT 1 FROM policy_attestations a
                   WHERE a.policy_id = p.id AND a.user_id = ? AND a.version = p.version
               )
             ORDER BY p.approved_at DESC",
            [$this->getCurrentOrgId(), $this->getCurrentUserId()]
        );
        $this->jsonSuccess(['pending' => $rows, 'count' => count($rows)]);
    }

    private function attClientIp(): ?string
    {
        $fwd = $_SERVER['HTTP_X_FORWARDED_FOR'] ?? '';
        if ($fwd) { return trim(explode(',', $fwd)[0]); }
        return $_SERVER['REMOTE_ADDR'] ?? null;
    }
}